Now he's saying Congress' decision to repeal it could actually increase costs.

Health and Human Services Secretary Tom Price.

Jabin Botsford | The Washington Post | Getty Images

Former Health and Human Services Secretary Tom Price used to say that Obamacare's individual mandate increased health-care costs. Now he's saying Congress' decision to repeal it could actually increase costs.

Lawmakers repealed the individual mandate, which penalized people who did not purchase health insurance, in the GOP tax reform bill President Donald Trump signed into law in December. The change goes into effect next year.

In a speech at the World Health Care Congress in Washington, Price argued on Tuesday that the move amounts to "nibbling at the sides" of the Affordable Care Act, long a target of the GOP and Trump, and that it would probably boost costs.

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"There are many, and I am one of them, who believes that that actually will harm the pool in the exchange market because you'll likely have individuals who are younger and healthier not participating in that market," he said. "And, consequently, that drives up the cost for other folks in that market."

Price led HHS last year as Trump and congressional Republicans worked to repeal and replace the Affordable Care Act, also known as Obamacare. He resigned in September after Politico uncovered he had been using taxpayer-funded private jets. Former Eli Lilly executive Alex Azar replaced him as HHS secretary.

The individual mandate taxed people for not having health insurance, an effort to incentivize people to buy coverage. In an interview with ABC News last year, Price said the requirement increases costs and makes it so people don't have coverage.

"Well, the individual mandate is one of those things that actually is driving up the cost for the American people in terms of coverage," Price said in the interview. "So what we're trying to do is make it so Obamacare is no longer harming the patients of this land. No longer driving up costs. No longer making it so they've got coverage, but no care. And the individual mandate is one of those things."